Significant age disparity in sexual relationships has been and remains a feature of couples in many cultures and societies. Although the more common pattern in heterosexual couples is an older man with a younger woman, the proportion of the converse (older woman/younger man) has risen significantly in many countries. In extreme cases, age disparity may be seen as dysfunctional (a paraphilia) if such relationships are pursued to the exclusion of all others and to the detriment of the partners.